Devices for acquiring internal tissue samples from a patient are generally known. For example, Jamshidi (U.S. Pat. No. 3,628,524) discloses a biopsy needle assembly which includes a needle and stylet. The disclosed biopsy needle may be utilized for sampling softer tissues such as liver, kidney, skin, and muscle tissue. The biopsy needle can also include a rasp-like exterior surface, a cutting edge, to be employed in biopsy needles used in obtaining bone and bone marrow biopsy specimens.
The needle disclosed by Jamshidi in U.S. Pat. No. 3,628,524 includes an elongate, substantially cylindrical body having a lumen therethrough. The device further includes a stylet which is similar in shape and length to the needle, which is adapted to be inserted into the needle in snug-fitting relation.
When assembled for use, the stylet is inserted into the needle and a locking pin is included to hold the stylet in place. When fully inserted the distal end of the stylet and needle are arranged in a predetermined relation to present a closed end surface which is utilized for penetrating tissue or bone.
Jamshidi further discloses that the stylet, as inserted into the needle and interlocked, exposes a tapered distal end. The tapered distal end is positioned in a predetermined relation with respect to the distal cutting edge on the needle whereby a closed symmetrical end surface is disposed substantially in a single plane. The needle is then inserted into the patient to a desired depth. Inserting the device can require penetration of bone which will necessitate rotating the needle and stylet assembly about its longitudinal axis to produce a boring effect caused by the rasp-like surfaces on the distal end of the needle.
When the distal end of the needle has reached the tissue from which the specimen is to be removed, the stylet is then removed from the needle and the needle may then again be revolved about its longitudinal axis while urging it forwardly. The moving of the needle produces a cutting action of the tissue and allows the specimen to be collected interiorly of the needle. After the specimen is collected, the needle is then removed from the patient.
Jamshidi (U.S. Pat. No. 3,598,108) discloses a similar biopsy device as that disclosed above. However, it is further disclosed that the stylet is first removed and the biopsy specimen is collected in a separate sleeve member which is inserted within the needle. The needle remains in place after the sample is taken so that a heat transfer means such as a microcauter or a cryoprobe may be introduced into the needle. These devices are utilized to reduce or prevent bleeding.
In U.S. Pat. No. 4,163,446, Jamshidi discloses a pad for use in combination with a bone marrow biopsy needle which is adapted to be slipped over the proximal end of the needle to provide an enlarged surface for distributing the pressure across the palm of the hand of the user. The device includes a generally disc-shaped palm engaging surface along a needle enveloping sleeve for releasable attachment to the biopsy needle.
Finally, Jamshidi (U.S. Pat. No. 3,630,192) discloses a biopsy needle having a sheath which is particularly adapted for use in the obtaining of biopsy samples from certain floating organs. The sheath disclosed by Jamshidi prevents accidental damage to such organs which would result in undesirable bleeding or other complications.
In utilizing all of these prior art devices, once a tissue sample is acquired within the lumen of the biopsy needle, the needle must be withdrawn with the sample included. However, there is nothing disclosed that will assure that the sample is held within the lumen of the needle during extraction. Thus, a problem arises, in use, when a portion of the tissue sample or fluid collected within the needle is allowed to drain into the track made by the incision. The problem is two-fold, in that the sample loss reduces the size of the specimen to be analyzed, and second, it is undesirable to deposit the tissue sample away from its source within the patient.
Accordingly, the need exists for a device for acquiring a tissue sample or a biopsy needle and method of use which prevents the loss of tissue sample or fluid sample during extraction of the needle. The device and method should include an apparatus which prevents accidental loss of any portion of the sample during removal of the biopsy needle assembly. Further, these features should be of simple design to prevent dramatically increasing the cost of the overall biopsy needle assembly and procedure.
The present invention addresses these needs as well as other problems associated with existing biopsy needles or devices for acquiring internal tissue samples. The present invention also offers further advantages over the prior art and solves problems associated therewith.